Potential-regulator for dynamos



No. 620,5l4. Patented Feb. 28, I899. A. A. TIRRILL.

POTENTIAL REGULATOR FUR DYNAIOS.

(Application fllod Apr. 28, 1898.) (No Model.) 7 3 Sheets-Sheet l.

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No. 620,5l4. Patented Feb. 28, I899. A. A. TIRRILL.

POTENTIAL REGULATOR FOR DYNAMOS.

(Apglication filed Apr. 28, 1898.)

Q 3 Sheets$haat 2.

(No Model.)

IIVVENTO/Z WITNESSES;

Jllen J. J'o'rrlb.

ATTORNEYS.

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A. A. TIRRILL.

POTENTIAL REGULATOR FOR DYNAIDS.

(Au limimi filed Apr. 28, 1898.)

3 Sheets-Sheat 3.

(No Model.)

WITNESSES:

ATTORNEYS.

mz uonms PETERS cu. FHOTD-LITHQ, WASHINGTON, n. c.

UNITED STATES PATENT OFFICE.

TO THE TIRRILL AUTOMATIC POTENTIAL LACONIA, NEW HAMPSHIRE.

REGULATOR COMPANY, OF

POTENTIAL-REGULATOR FOR DYNAM OS.

SPECIFICATION forming part of Letters Patent No. 620,514, dated February28, 1899.

Application filed April 28, 1898. Serial No. 679,079. (No model.) I

To all whom it may concern:

Be it known that I, ALLEN AUGUSTUS TIR- RILL, of WVhitefield, in thecounty of Coos and State of New Hampshire, have invented a new anduseful Improvement in Automatic Potential-Regulators for Dynamos, ofwhich the following is a specification.

In a prior patent granted to me in connection with Philip S. Tirrill asjoint inventors, January 4, 1898, No. 596,923, we showed and describedan automatic potential-regulator for dynamos whose object was toautomatically regulate the potential or voltage on the snpply-wires, sothat an even potential shall always be maintained on said wiresnotwithstanding the varying tax or demand made upon the supply-wires bythe starting and stopping of electric motors or the throwing in and outof circuit electric lights, 850. My present invention is an improvementupon that machine, designed to overcome certain objections whichexperience has developed and chief among which is the tendency of thesolenoid contact-points to stick, in obviating which I employ a relayanda second set of contact-points and a separate or supplementalcircuit, and also certain other features which will be hereinafter fullyshown and'described with reference to the drawings, in which- Figure 1is a front elevation of the instrument; Fig. 2, a vertical longitudinalsection on line 2 2 of Fig. 1; Fig. 3, a diagram of circuits, and Fig. 4is an enlarged detail in perspective of the solenoid-contacts.

In the drawings, A A represent the hollow coils of two solenoids,arranged in vertical position and fixed within a suitable case on anon-conducting backing of marble or slate. In the center of these hollowcoils there vibrate freely in vertical direction the soft-iron cores AA, made preferably of laminated wire and suitably incased with rubbershells. The tops of these cores are connected by stem to and suspendedfrom the outer ends of delicately-balanced levers B B, of metal, whichare fulcrumed upon pivots within supporting frames or brackets h b, andat their inner ends are lapped for a loose-jointed connection and arepulled down by a spring D, having a stem 61 and adjusting devices at itslower end. I As so far described, the mechanical devices aresubstantially the same as those referred to in said previous patent. Tohold the cores A A against swinging about and dragging with a frictionagainst the inside of the cores, I extend a stem .9 from the lower endof each core and cause this to be guidedin an arm 5 so as to alwaysmaintain an exactly concentric position to the coils Without allowingthe cores to touch the inside of the coils at all. The lever B has fixedto it at its inner end a metal boss a, carrying a platinumcontact-faceax. (See Fig. 4.) The other lever B where it laps over B isprovided with a metal disk or roller (1 arranged in a vertical plane andbearing upon the end of lever B, so as to roll in contact therewith whenthe inner ends of the levers rise and fall, so as to reduce friction atthe point of articulation.

Just above the end of lever B there is arranged a flat spring (tadjusted downwardly by a set screw o mounted in a stud a, projectingfrom the marble back of the instr11- ment. This spring serves to quicklythrow down the inner ends of the levers when they rise and strikeagainst the same, and its tension'may be adjusted to act sooner orlater, as circumstances may render desirable.

Just below the platinum contact-points a w there is another, 0 as. Thisis mounted upon a flat horizontal spring 0 adjusted longitudinally byscrews 0 in a bracketshaped piece 0 whose horizontal member is slottedand clamped to a bracket 0, projecting from the marble back, by means ofa nut c and screw 0 1 and i are binding-posts, which connect with thetwo upper wires of the circuit to be regulated.

2 and 3 are binding-posts connecting with the wires of the shunt-circuitthat energizes the field-magnets of the dynamo, these connections beingsubstantially the same as those shown in said previous patent. Instead,however, of connecting the binding-posts 2 and 3 to the terminalcontacts at the inner ends of levers B B, as in said previous patent, Iconnect them to other contact-points a and 0, (see Fig. 3,) controlledbya relay-magnet M, placed in an independent or supplemental circuittaken from the supply-wires through binding-posts l and i. The heavyblack lines in Fig. 3 show this supplemental circuit,

which constitutes one of the principal features of my improvement. Thelight continuous line from binding-posts 1 to 4 shows the main circuitas originally used and which I term the primary branch circuit, and thedotted line the dynamo shunt-circuit as originally used. Referring nowto Fig. 1 again, I will trace these circuits through the instrument andcomplete the detailed description 7 cuit is simply for the purpose ofpreventing,

the burning out of the coils M, A, and A from too great electricalenergy. This resistance consists of a series of non-conducting slabs,each with a single layer of silk-covered German-silver wire, the spacingof these coils on the separate cores being for the purpose of allowing athorough ventilation and preventing the heating of the coil, as shown inFig. 2. The supplemental circuit, which constitutes one of my addedfeatures of improvement, is introduced (see Figs. 1 and 3) through thebinding-posts 1" and 4. This is taken off the supply-wires X and X asfollows: Coming in from supply-wire X to post 1 to wire 10 it goes to ametal contact 11, which is an insulated stop of an armature 12 of magnetM. From this stop-contact it passes through the normally-closed armature12, which is constantly attracted by the constantly-energized conditionof magnet M, from armature 12 to wire 13 and solenoid-lever B, andwhenever contacts a m and c ware closed it passes through them to wire14, the coils of relay M to wire 15, and the bindingpost 4 to thesupply-wire X of opposite polarity. The relay-magnet M has an armature1G with a platinum point a playing upon a platinum point e. The point ais connected by wire 10 with binding-post 3 and wire 17 with one pole ofthe dynamo field-magnet, and the other point 0 is connected by wire 18to binding-post 2 and wire 19 with the other pole of the dynamo. Thecontact-points a and c, it will be seen, constitute, therefore, theterminals of the shunt-circuit of the dynamo field-1nagnets, in whichshunt-circuit, as shown in said previous patent, is arranged theresistance It, and in the action of the present invention when thecurrent on the supply-wires falls in potential this shunt-circuit isclosed through the contacts a c, and the resistance R being cut outthere is a greater energizing of the field-magnets, and the dynamo ismade to instantly bring up the potential of the line in an automaticmanner to compensate for its reduction made by the throwing in oflights, motors, or other uses of the current. In said previous patentthe terminals of this shunt-circuit were closed by the direct action ofthe solenoid-lever B at a 0;. This, however, was found to beobjectionable, for the reason that the great amount of energy that theywere obliged to carry for the regulation of large dynamos, together withthe induction, would cause a spark at the points, and after the sparkwas broken by the condenser said points would come together and stickhard enough to require from one to three volts above the normal voltageto open them again, thus destroying the sensitiveness of the regulationand causing a flickering of the lights on the line. My present inventionis designed to relieve the sensitive contact-points from this greatamount of energy, and this I accomplish by the supplemental circuitthrough the binding-posts 1 and 4 and the relay M, the shunt-circuit ofthe dynamo being controlled through terminals worked by the relay M andthe relay M by the supplemental circuit worked by the solenoidcontact-points a a: and c a.

Referring now to Fig. 3 particularly and remembering that magnet M isalways energized and the armature 12 always resting normally upon stop11 whenever the potential on the line X X falls, the inner ends oflevers B B descend and contacts a x and c :0 come together. Thiscompletes the supplemental circuit through relay-magnet M, andenergizing relay-magnet M closes the contact-terminals (I, c of theshunt-circuit of the dynamo field-magnets, cutting out resistance R andat once increasing the potential on the line correspondingly to the taxmade upon it Vhen equilibrium is restored and the potential is broughtup to normal, the solenoid-coils A A lift the inner ends of levers B Bagainst the spring D, break contact at a :0 and c as, and also instantlybreaking contact at a c and again throwing in the resistance E into theshunt-circuit. Thus a sensitive automatic regulation is obtained at alltimes and under all conditions.

I will now describe the function of the electromagnet M.

It will be seen that it the solenoid-circuit from 1 to 4 be broken atany time by any accident, as the falling of a tree or any similar cause,then the spring D would hold the contacts a so and c a; into permanentclosure, rheostatR would be permanently out out, and the potential onthe line would run up to a high and dangerous pitch. To prevent this,the supplementary circuit from 1 to 4: is made to be broken by anyaccidental breakage of the main solenoid-circuit through theinstrumentality of the electromagnet M and contact-points 11 and 12, forif the main circuit which passes through coils of magnet M be thusbroken the magnet M being demagnetized armature 12 flies up and contactis broken between 11 and 12, and as these are also terminals of thesupplementary circuit it will be seen that the supplementary circuit isbroken, contacts a so and c 00 are rendered null in effect, and even ifthey be closed no current flows through the supplementary circuits andthe terminals a c of the shunt from the dynamo are kept permanently openand the line then works with the constant resistance of the rheostat-R.

\Vhen more than one dynamo is employed on the supply-wires, it isobvious that the relays M and the shunt-circuits of the dynam os may bemultiplied to correspond with the number of dynamos used.

In some applications of my invention it may be desirable to reduce theenergy of the solenoid-coils A A, and for this purpose I may compoundthe same by winding coils of wire A A upon the same in oppositedirection to the solenoid-coils. These additional coils A have a seriesof binding-screws A arranged at different points along theirlength, and0011- nections A A A are arranged to throw the current through anyportion of these added coils to choke or retard the working current inthe solenoid-coils to any desired degree.

In illustrating my invention 1 have shown two solenoid-coils A A and twolevers B B; but it is obvious that my invention might be carried outwith only one such coil and lever, and my invent-ion is designed to havethis scope. I prefer, however, to use the two coils and two levers forthe reason that it is a more efficient and more symmetrical apparatus.

In connection with my regulator as thus described I may also use acondenser as shown in said previous patent referred to.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a potential-regulator for a dynamo, the combination with the mainsupply-wires, and a norm ally-closed primary branch circuit connected tothe supply-wires and provided with one or more operating-helices; of apair of contactterminals arranged, to be opened or closed upon eachother by the action of said helices, a supplementary branch circuitconnected also to the supply-wires and terminating in the pair ofcontacts, aforementioned,a relay arranged in this supplementary circuit,a shunt-circuit connecting with the dynamo and provided with a rheostat,said shunt-circuit having two terminals extended to the armature of therelay and being opened orclosed by the same substantially as and for thepurpose described.

2. In a potential-regulator for a dynamo, the combination with the mainsupply-wires; of a solenoid-regulator circuit connected to the supply, ashunt-circuit from the dynamo field-magnets with rheostat, asupplementary circuit and relay, the relay being worked by thissupplementary circuit and controlling the terminals of theshunt-circuit, and the supplementary circuit having terminals operatedby the solenoid-circuit, and also an electromagnet placed in thesolenoid-circuit and having an armature arranged when attracted to closethe supplementary circuit, and to open the same and render itinoperative whenever the solenoid-circuit is accidentally brokensubstantially as and for the purpose described.

3. In a potential-regulator for dynamos, the combination of thesolenoid-coils, their cores, and the levers B B bearing contactpoint asdescribed, a spring for drawing the inner ends down, and a superposedadjustable spring arranged above the inner ends of the levers to beimpacted against by the rise of the inner ends of the levers whereby thelatter are made to quickly return substantially as described.

4. In a potentiahregulator for dynamos, the combination with thesolenoid-coils, their cores, and the levers B B having contactpoints asdescribed, the inner ends of said levers being lapped and the upper onehaving a spring to draw it down and a rotary disk or roller resting uponthe lower lever, said disk being arranged in the plane of the levers toform a sensitive articulation substantially as described.

5. In a potential-regulator for dynamos, the combination with thesolenoid-coils, their cores, and the levers B Bhaving contactpoint asdescribed, a subjacent spring bearing a contact-point, and aclamping-support for said spring made adjustable to grasp said spring atdifferent positions along its length to vary its range of vibrationsubstantially as and for the purpose described.

ALLEN AUGUSTUS TIRRILL.

Witnesses:

Soorr I-I. SLOANE, RAYMOND E. SMITH.

